Electronic devices, (e.g., laptops, tablets, notebooks, netbooks, personal digital assistants (PDAs), personal computers, mobile phones, etc.) often include a variety of wireless communication capabilities. Such capabilities may involve communications in higher frequency ranges of the communication spectrum, such as in the millimeter wave (mmWave) region, e.g., the 60 Gigahertz (GHz) frequency band. These higher frequency ranges can advantageously offer higher data rates.
A mmWave propagation has a few major distinctive features in comparison with lower frequency bands, e.g., the frequency bands of 2.4-5 GHz. For example, the mmWave propagation may have a propagation loss greater than the propagation loss in the lower frequency bands, and may have Quasi-optical propagation properties.
A mmWave communication system may use high-gain directional antennas to compensate for large path loss and/or employ beam-steering techniques. Design of appropriate antenna system and/or further signal processing may be an important aspect of mmWave communication system development.
Multi-element phased antenna arrays may be used, for example, for creation of a directional antenna pattern. A phased antenna array may form a directive antenna pattern or a beam, which may be steered by setting appropriate signal phases at the antenna elements.
Various regulations and limitations, e.g., government regulations and limitations, may apply to transmissions performed over one or more frequency bands. For example, the United States Federal Communications Commission (FCC) imposes a peak emission limit of a maximum power density of Smax=18 μW/cm2 for a millimeter-wave band, e.g., the frequency band of 59.05-64 GHz, as measured three meters from the transmit antenna, and a total transmitted power limit Pmax=500 mW. Similar limitations exist in regulations of other countries and/or for other frequency bands.